QC Material Stability
Stability has a number of different definitions, however, the most relevant to clinical diagnostics, and indeed quality control sera, is the “resistance to chemical change or physical disintegration”. Much like a chain, your quality control system is only as strong as its weakest link, or in this case analyte.
Whilst we appear to be stating the obvious here, this might not be as straightforward as it first appears. The product literature you peruse will help you decide what control best suits your needs, whilst many companies will state their control stability in the literature there are some instances where all may not be as it first appears. It is also important to note that some manufacturers may not make stability claims for some of the analytes listed in their control material. In such instances, you are required to validate these in-house, taking up precious time and resources.
Dig a Little Deeper
Whilst we understand that some analytes do have limitations due to their inherent nature, misleading analyte claims can cost the laboratory both time and money. In a recent survey conducted by Randox, 65.5% of respondents indicated that they felt stability was a ‘Very Important’ QC feature. As such it’s important that you look beyond the sales literature when it comes to control stability. Look out for exceptions in the small print of the control kit inserts. For example, if a control has a stability claim of 7 days at 2-8oC and a routine analyte like Cholesterol has a stability claim of just 2 days at 2-8oC then the true stability of the control is only 2 days. In such instances, there is a lot of potential for waste, as laboratories will be required to prepare a new vial of QC material every 2 days leading to increased costs and time. However, if you dig a little deeper into the controls and always read the small print, you could avoid such issues.
How can Randox Acusera benefit you?
For more than 30 years Randox has been shaping the future of clinical diagnostics with our pioneering high quality, cost effective laboratory solutions. Quality Control is our passion, we believe in producing high-quality material that can help streamline procedures, whilst saving money for laboratories of all sizes and budgets. We pride ourselves in not misleading our customers with false stability claims for our controls. With controls such as our Liquid Cardiac and Specific Proteins Controls, you could benefit from a 30-day open vial stability for all analytes, without exception.
By employing our Randox Acusera quality control materials you could benefit from;
Commutable controls, ensuring a matrix that reacts to the test system in the same manner as a patient sample, enabling an accurate and reliable assessment of instrument performance.
Accurate target values that won’t shift throughout the shelf life of the controls, eliminating the need to spend valuable time and money assigning values in-house.
Consolidation of test menu with controls comprising up to 100 analytes, reducing preparation time and storage space required.
Analytes present at clinically relevant levels ensuring accurate test system performance across the clinical range, maximising laboratory efficiency by eliminating the need to purchase additional high or low-level controls at extra expense.
True third party controls designed to provide an unbiased assessment of performance, our Acusera controls have not been manufactured in line with or optimised for use with any particular reagent, method or instrument.
For more information on any of our products, or to request a consultation from one of our QC Consultants, contact us via email@example.com.
Measurement Uncertainty (MU) relates to the margin of doubt that exists for the result of any measurement, as well as how significant the doubt is. For example, a piece of string may measure 20 cm plus or minus 1 cm, at the 95% confidence level. As a result, this could be written: 20 cm ±1 cm, with a confidence of 95%. Therefore, we are 95% sure that the piece of string is between 19 cm and 21 cm long.
Standards such as ISO 15189 require that the laboratory must determine uncertainty for each test. However, they have not specified how this should be done.
How do we calculate Measurement Uncertainty using QC data?
Employing your QC data to calculate uncertainty makes several assumptions; your test system is under control, the patient samples are treated in the same manner as your controls and gross outliers have been removed. If you choose to use your QC data to calculate this you should ensure that you use a commutable control with a matrix similar to that of a patient sample, with analytes present at clinically relevant levels
To calculate MU, labs must look at the intra-assay precision and inter-assay precision of their test.
Intra-assay precision: Sometimes known as ‘within run’ precision, is where 20 or more replicates of the same sample are run at the same time, under the same conditions (calculated from a single experiment). Intra-assay precision helps to assess systematic uncertainties
Inter-assay precision: Sometimes known as ‘between run’ precision, is where 20 or more replicates are run at different times – e.g. 1 replicate every day for 20 days (can be calculated from routine IQC data). Inter-assay precision can help identify random uncertainties within the test system.
*The Australian Association of Clinical Biochemists (AACB) recommends that at least 6 months’ worth of QC data are used when calculating the inter-assay precision1.
Once the data is collected, you must calculate the standard error of the mean (SEM) of the intra-assay precision (A) and the SD of the inter-assay precision (B) in order to measure the uncertainty (u). Once A and B have been calculated, they need to be squared, added together and the square root of the sum found:
As uncertainty is calculated as SD and 1SD is equal to 68% confidence on a standard Gaussian curve, we can conclude that if we multiply using a coverage factor of 2, we can attain 2SD confidence of 95%. This is known as the Expanded Uncertainty (U):
What is the Advantage of Measurement Uncertainty for a lab?
Labs need to carry out MU as it is a requirement of ISO 15189. It states: “The laboratory shall determine measurement uncertainty for each measurement procedure, in the examination phases used to report measured quantity values on patients’ samples. The laboratory shall define the performance requirements for the measurement uncertainty of each measurement procedure and regularly review estimates of measurement uncertainty”.
MU also helps determine whether the difference between two results is negligible due to uncertainty or significant due to a genuine change in condition of the patient; giving labs a greater confidence in reported results.
How can Randox help?
Our new Acusera 24.7 Live Online software provides automatic calculation of MU, saving valuable time and helping labs meet ISO 15189 requirements with ease.
Contact firstname.lastname@example.org to find out how your lab can benefit from Acusera 24.7 Live Online
According to the NHS Litigation Authority; in 2015 within the UK alone, £193,680,744.30 was spent on ‘wrong diagnosis’ or ‘failed/delayed diagnosis’ causing huge financial strain and impact on labs.
With approximately 75% of clinical decisions and diagnosis based on laboratory test results. The only way to guarantee a high degree of accuracy is to implement a good Quality Control plan. The importance of this is recognised globally, several bodies exist internationally including ISO (International organisation for standardisation) who have developed a set of guidelines and quality systems to ensure the reliability of laboratory test results.
So what can you do to improve accuracy and reliability?
Choose a third party QC
ISO 151589:2012 Section 18.104.22.168 states that “the use of third party control materials should be considered, either instead of, or in addition to, any control materials supplied by the reagent or instrument manufacturer”.
First Party Controls are those manufactured by the instrument/reagent manufacturer. These controls are optimised specifically for use with the manufacturers test system and therefore will mask a multitude of weaknesses. First Party Controls tend to result in perceived accuracy and a biased assessment of performance.
Third Party Controls on the other hand are designed to be completely independent and are not optimised for use with a specific test or system. Leading manufacturers of third party controls will assign target values based on data collected from thousands of independent laboratories, ensuring the availability of statistically robust multi-method, multi-analyser data. Therefore laboratories using Third Party Controls can be assured of unbiased error detection across multiple platforms.
Randox Acusera is a world leading manufacturer of true third party controls providing a cost effective, high quality solution for any laboratory-regardless of size or budget.
Look out for QC samples with clinically relevant concentrations
ISO 15189:2012 states that ‘The laboratory should choose concentrations of control materials wherever possible, especially at or near clinical decision values, which ensure the validity of decisions made’.
It is important to assess the full clinical range of an assay i.e. the range between the lowest and highest results which can be reliably reported. In order to make sure a laboratory instrument is performing accurately across the full clinical range and in particular at the medical decision level, QC materials that cover low, normal and elevated concentrations should be used.
Due to the superior manufacturing process used by Randox, QC target values consistently cover the MDL of tests. By ensuring the controls in use cover clinical decision levels laboratories can be confident of the reliability and accuracy of the patient results they release.
Opt for a commutable control material
A good QC material has many essential properties but above all, controls must perform consistently and reflect the performance of patient samples – if a control meets these requirements then we can say it is commutable. Having a commutable control would aid in the prevention of incorrect patient results because they replicate the performance of a patient sample and react to the test system in a similar manner. Use of a commutable control will also reduce costly shifts in QC target values when reagent batch is changed.
At Randox we take quality seriously, that’s why all QC products are manufactured to the highest possible standard, delivering controls of unrivalled quality. Designed to be commutable, the Acusera range will ensure accurate and reliable instrument performance while simultaneously helping laboratories to meet ISO 15189:2012 requirements. A good QC process will include the use of Third Party Controls, Clinically Relevant Concentrations and controls which can be described as commutable. By employing Quality Control’s that encompass these traits, a laboratory professional can be certain that they have taken the necessary steps to decrease incorrect results and therefore potential misdiagnosis.
Being part of a global company offers endless opportunities including career growth, international travel and the chance to relocate somewhere new and exciting, or to take your job back home!
Travis Lai, one of our business development executives for Randox Quality Control took the opportunity to relocate from London to Malaysia in order to be closer to his family back in December 2015! Read our Q&A below to find out what it’s like to work for Randox and how Travis enjoys being closer to his family and friends.
Hi Travis, can you tell us a little bit about your background working for Randox?
I have been with Randox now for nearly three years working as a business development executive for Randox Quality Control. As part of my role I am constantly developing new sales leads, developing relationships with current and new customers, in charge of distributor management and planning and overseeing new marketing initiatives which all aim to grow the Quality Control division at Randox.
How did you find working in the London?
When I first started working for Randox I was based in the London Wall office. I had been to London a few times before I joined Randox and already knew a few people who were living in London which was nice. London is a very vibrant and multi-cultural city with lots to do and see. It was a big change for me in the beginning as it took me a while to get used to the food and of course the weather! I made sure to buy a raincoat during my first week!
What made you decide to relocate home to Malaysia?
I worked in London from April 2014 to Dec 2015 before I took the opportunity to return home to Malaysia due to a family concern. I had been thinking about it for a while and when the opportunity came Randox approved my application for relocation. I was very pleased that I was given this unique opportunity as it’s quite rare that employees are able to transfer from London to as far as Asia for a job role. But that’s one of the perks working in a global organisation, you get to experience things that you wouldn’t get the opportunity to do so elsewhere– I am extremely grateful that I got the opportunity to move back home for work.
Were you able to continue to work in the same job role once you moved home?
Yes, I was able to continue to work as a business development executive for Randox Quality Control which is great, the only thing that changed was my location.
What do you enjoy the most about being home in Malaysia?
I love being closer to my family and friends here at home, I think that’s probably the best thing for me I missed them a lot when I was living in London. It’s also great to get back to the sunny weather, Malaysia is quite warm all year around so there isn’t much of a need for a raincoat over here and I also love the food. My favourite dish is called Nasi lemak, it is a Malay fragrant rice dish cooked in coconut milk and considered the national dish. In terms of work, it’s useful that I am closer to the end users and distributors. This really comes in handy when I need to get in touch with distributors urgently and I don’t have to worry about time differences.
If you are interested in joining our global team make sure that you check out Randox careers website to see what new opportunities we have for you.
T’was the week before Christmas and all through the lab not a thing could be heard not even a sound. The analyser lay silent asleep in the corner, the lab staff at home dreaming of a few days’ rest, only a few more days to go before the big day!
The big man in red, what will he bring those who already have everything? Peace, happiness and health for their loved ones throughout the festive break, that would be the wish for everyone to make. And what better way to ensure they stay healthy, well it all begins in the laboratory…
An important consideration to remember when choosing your lab Quality Control (QC) is that approximately 70% of clinical decisions are based on laboratory test results. It is therefore essential that the results gained from laboratory testing are accurate and reliable in order to provide the appropriate treatment and avoid or prevent potential misdiagnosis.
Patient results are of the utmost importance for a laboratory and therefore running the best Quality Control material should be at the top of their agenda. QC material should have a number of features that allow a lab to judge the overall quality of their output. These features include the controls ability to be commutable (which means how well it reacts as a replicate of a patient sample), is it a true third party control that has been manufactured to provide an independent and unbiased assessment of performance, does your control come with clinically relevant levels and does it have a long shelf life as well as a good open vial or reconstituted stability? These are the questions lab staff will be asking themselves when deciding on what QC is the right QC.
So stay off Santa’s naughty list by providing accurate and reliable patient test results, do this by employing Randox QC in your laboratory. Our controls have been designed to deliver significant cost savings without sacrificing on quality. With consolidated controls (combining up to 100 analytes in a single vial) your lab can reduce QC costs and preparation time, the inclusion of analytes present at clinical decision levels will eradicate the need for additional controls and because of our long shelf life (2 years for liquid controls, 4 years for lyophilised) and excellent stability claims your laboratory can be sure that expensive lot changes will be a thing of the past! Our controls can be described as true third party and this, combined with the commutable nature of the controls, leads to us being able to claim that we have the best Quality Control material around.
So this Christmas when deciding what QC to choose – make sure you look no further than Randox Quality Control. Our QC family is known as Acusera and our product offering includes QC and calibrator material, Interlaboratory Data Management Program (Acusera 24.7), the world’s largest international EQA/PT scheme better known as RIQAS and the newest addition to the family, Linearity or Calibration Verification material.
We have packages for every lab regardless of size and budget and we guarantee you will become ho-ho-hooked on Randox QC.
Wishing you all season’s greetings and a prosperous New Year from everyone at Randox QC.
An important consideration when choosing your Quality Control material that is often overlooked is the shelf life of the control. With every new lot of control extensive validation studies must be performed. Regulatory bodies such as CLIA require new lot numbers to be evaluated before routine use in the laboratory. For example, CLIA has instructed that any new control lot to be run alongside patient samples will need to be verified alongside the old lot of control. The process is designed to give laboratory professionals confidence in the new material and ensure it is fit for purpose before implementing it in the lab.
As part of the validation process laboratories are required to assay both the old and new lots side by side. The current lot is then used to help verify if the new lot will be acceptable to run within the lab. Such validation studies can be very costly for a lab as well as being extremely time consuming – with some studies taking up to a month to complete! By choosing a control with a longer shelf life laboratories can aim to use the same lot of control for a longer time period. Ultimately this means fewer lot changes and minimal inconvenience for the lab. With a shelf life of 2 years for liquid controls and up to 4 years for lyophilised, coupled with unrivalled stability claims, employing Randox Quality Control in your laboratory will ensure that expensive lot changes will be a thing of the past. Our comprehensive control offering is guaranteed to increase efficiency and reduce costs in any laboratory without compromising on quality.
Contact us today to find out more information on our Acusera range of Quality Controls.
Quality control has recently become crucial in the Point-of-Care (POC) field due to the introduction of ISO 22870 regulations and increased focus in patient safety. Quality control is critical in reducing turnaround time and saving money.
There is now an international standard specifically for POC testing, ISO 22870. This standard is intended to be used in conjunction with the standard for medical laboratories, ISO 15189. This means that aspects relating to Point-of-Care such as training, competence and documentation should be carefully planned, implemented and governed by a quality management system and there is a requirement for QC and EQA to be performed, where available.
POCT is typically carried out by non-laboratory staff, therefore when selecting the appropriate IQC material for POCT there are a number of key characteristics you must consider;
- Format of the material – QC material employed should be liquid stable, requiring no preparation, reducing the likelihood of human error and increasing convenience.
- Value assignment – all values must be accurately assigned. Look out for suppliers who use a large number of independent labs to determine the target value.
- Third party controls – manufactured independently from any specific instrument or method third party controls are designed to deliver unbiased performance assessment.
- Storage – for convenience controls should be liquid stable, as these can be easily stored in a fridge at 2oC – 8oC and won’t need to be shipped on dry ice.
- Stability – a control with a good open vial stability will mean that it can be used for longer with less waste produced, meaning it is more convenient for the medical professional to use.
- Transportation– the liquid stable controls can be conveniently stored at 2oC – 8oC reducing the need to ship on dry ice
- Minimal training– easy to use with little training required, therefore suitable for use by non-laboratory personnel
In addition to IQC, External Quality Assessment (EQA) must also be employed to ensure a comprehensive review of test system performance. It is best to select a programme that offers frequent reporting with a large database of users. This will enable rapid error identification and ultimately accurate and reliable patient testing.
Our Acusera liquid ready-to-use controls include:
- Blood Gas Control– A liquid stable control provided in easy to open ampoules for added convenience and ease-of-use. Assayed, method specific target values are provided for the most common blood gas instruments.
- Liquid Cardiac Control– This is a highly convenient liquid stable cardiac control offering excellent consistency. Assayed, instrument specific target values are provided for 8 cardiac markers, enabling flexibility and consolidation.
- Liquid Urinalysis Control– Liquid control that is compatible for use with both manual and automated methods of dipstick analysis. Available in convenient 12ml vials or 25ml dropper bottles with assayed ranges provided for 13 parameters covering the chemical examination of urine specimens.
- Liquid HbA1c Control– This is another highly convenient liquid ready-to-use control. With an open vial stability of 30 days, keeping waste and costs to a minimum.
Complementary EQA programmes are also available to meet the needs of ISO 22870.
IQCP stands for Individualized Quality Control Plan, and it is an all-inclusive approach to creating a customized quality control plan for a laboratory.
IQCP focuses on assuring quality in the lab using more in-depth means than simply carrying out a certain number of QC tests at a specific frequency. Many different aspects of laboratory operations will be evaluated, such as the test system, reagents, environment, testing personnel etc.
As of January 2016, many labs in and outside the USA have implemented their IQCP’s, but what impact has this had on day-to-day operations?
In order to gauge the overall effectiveness and user-experience of implementing IQCP, Westgard QC1 conducted a survey for all IQCP participants both in the USA and globally.
Opinions were mixed regarding the effectiveness of IQCP:
- Some users found that IQCP decreased the number of QC materials required
- There is a greater emphasis on the pre and post-analytic phases of testing, thus improving process error identification
- Over half of global survey participants revealed that their IQCP identified unacceptable risk(s) in their test system, thereby creating a more robust process
- Of the labs whose IQCP’s were inspected in the USA, 96.3% were deemed adequate by the relevant regulatory bodyies
- Identification of errors can lead to additional personnel training, thereby increasing the knowledge and expertise of laboratory staff
- Due to the length of time taken to create a single IQCP, coupled with the additional expense, several survey participants found that the benefits of IQCP did not justify using so many resources in its implementation
- Many labs raised concerns regarding the availability of guidance in developing an IQCP. Participants complained that useful guidelines were not provided quickly enough, and labs had to rush their IQCP implementation.
- Several survey participants felt as though there was widespread confusion over IQCP. Participants highlighted that the volume of questions from laboratory professionals proves that IQCP was not introduced by regulatory bodies in an organized or effective manner
- Some labs surveyed voiced the opinion that IQCP evaluation needs to be more standardized, and that inspections can either be too lenient or too stringent.
As with any new system, feedback is important for further refinement. IQCP appears to be a step in the right direction for the advancement of laboratory QC. According to Westgard’s survey1, only around 30% of US respondents were satisfied, showing that labs still feel improvements need to be made. Inspectoral standardization, or more concise, straightforward guidelines on IQCP implementation could be potential improvements for regulatory bodies to consider.
We would love to know your thoughts on the subject. Send us an email at email@example.com.
Westgard QC. (2016).2016 IQCP Users Survey. Available: https://www.westgard.com/iqcp-user-survey-comments.htm. Last accessed 25-Oct-16.
Don’t Get Tricked This Halloween – Treat Your Lab to Randox True Third Party Controls Today!
Halloween – a celebration observed by many countries around the world on a yearly basis. Falling on October 31st this holiday is a chance for people to dress up, carve pumpkins, bob for apples, attend costume parties, trick-or-treat and tell scary stories.
It just so happens that we have a scary story for you – and what makes this story even scarier is that it’s a true story!
Our story starts off in a medical laboratory. This laboratory was running QC on their machine as they would do every day. Getting accurate results with no faults or problems arising from their machine, this laboratory was happy with how things were going – until one day when it all went wrong!
Having run their EQA/PT samples, the laboratory found themselves reviewing their report with shock –they noticed a large negative bias. To their horror the perceived ‘accuracy’ they had once achieved was now no longer the case. Right away the laboratory professional’s thoughts turned to the fact that approx. 70% of all clinical decisions are based on laboratory test results, meaning it is essential that the results provided are accurate and reliable in order to prevent potential misdiagnosis or inappropriate treatment. Had they sent incorrect patient results to the clinicians? Had a patient been misdiagnosed? Many thoughts fluttered around in their heads.
The laboratory repeated their QC and found that the results obtained were almost identical to the previous run. The laboratory knew there must be a problem with their QC or their instrument, so they began the troubleshooting process. Nothing. Nada. Zilch. “What was going on?” was the question on the lips of the laboratory professionals.
One of the laboratory professionals then stumbled across a case study that took place in the University of Verona and Academic Hospital of Parma, Italy. The study was related to a field recall of Intact PTH, the reagent was recalled after falsely elevated patient results were discovered. The alarming thing was that the same elevated performance was not identified by the instrument manufacturer’s control. The study reported that due to this issue there was potential for 40,000 inaccurate patient results from just 18 labs in the Lombardy region of Italy. The study also concluded that the issue could have been prevented if a third-party control, independent from calibrator materials had been used.
This PTH case study got the laboratory thinking that maybe they should source a true third party manufacturer… Having sampled a third party QC, the lab found their results now mirrored that of their EQA and patient samples and as such proceeded to make the switch from first party to third party.
The moral of this story is that first party controls can sometimes “trick” the lab into thinking their performance is acceptable. Quite often target values provided with first party quality controls are in the middle of the analytical range thus masking the issues at the low and high ends of the assay range. Laboratory professionals should “treat” their labs to the best QC material. ISO 15189 highlights that the “use of independent third party control materials should be considered, either instead of, or in addition to, any control materials supplied by the reagent or instrument manufacturer”. So this Halloween don’t randomly choose your QC supplier, treat your laboratory to the best, Randox QC.
All Randox controls are manufactured independently of any instrument or reagent, and designed for use with multiple instruments and methods ensuring, unbiased performance assessment.
Following recommendations from recognized institutions such as ISO and CLIA, more laboratories are using third party controls than ever before. However, great care should be taken when choosing which third party control to use. A number of factors should be considered, and primarily among these is whether the control challenges the complete Clinical Range and the Medical Decision Levels. ISO 15189:2012 states that ‘The laboratory should choose concentrations of control materials wherever possible, especially at or near clinical decision values, which ensure the validity of decisions made’.
Measuring the Complete Clinical Range
It is important to assess the full clinical range of an assay i.e. the range between the lowest and highest results which can be reliably reported. In order to make sure a laboratory instrument is working across the full clinical range, a QC which covers low, normal and elevated concentrations must be used.
Question: “If the full clinical range isn’t covered by QC, how will we know whether patient results which fall outside the range of quality controls are accurately reported?”
What are Medical Decision Levels?
Medical Decision Levels (MDL) are the analyte values at which medical professionals can determine whether a patient may be suffering from a certain condition. The MDL is determined by a consensus of medical professionals and clinical research. Patients’ test results are compared to the MDL and appropriate diagnoses or medical interventions can be made.
For example, the MDL of Glucose can indicate a certain diabetic status:
|Analyte||Medical Decision Level||Diagnostic Status|
|Glucose (fasting)||<100 mg/dL||Non-Diabetic|
Many QC manufacturers ‘cut corners’ in an attempt to keep costs down, which often results in the sale of controls which do not cover the complete clinical range or vital medical decision levels. Below is an example of the Glucose concentrations present in a competitor control:
Competitor Chemistry Control Level 1 – 68 mg/dL
Competitor Chemistry Control Level 2 – 134 mg/dL
Competitor Chemistry Control Level 3 – 386 mg/dL
In the examples above, the competitor’s level 1 control covers the non-diabetic MDL, but the level 2 control is not within the ‘Pre-Diabetic’ decision range. The level 3 control is also much higher than can be expected for an elevated diabetic patient result (200 mg/dL or more).
Due to the superior manufacturing process used by Randox, QC target values are consistently within the MDL of tests. For example, the Glucose concentrations present in our Liquid Assayed Chemistry Premium Plus control are:
Level 1 – 57 mg/dL
Level 2 – 114 mg/dL
Level 3 – 236 mg/dL
The MDL for Glucose is covered by the Randox control, meaning laboratory professionals can be confident that patient results will be accurately interpreted.
Immunoassay Medical Decision Levels
Controls which cover the MDL can reduce the number of Quality Controls required by laboratories. For example, Randox Acusera Lyophilised Immunoassay Controls contain particularly low levels of TSH, Ferritin and Vitamin B12 in the Level 1 control, eliminating the need for an additional control at extra expense:
|Analyte||Medical Decision Level||Randox Level 1 IA Control||Competitor Level 1 IA Control|
|TSH||0.1 or 0.27 uU/mL||0.15uU/mL||0.37 uU/mL|
|Vitamin B12||190 pmol/L||174 pmol/L||327 pmol/L|
|Ferritin||12 ng/mL||11.1 ng/mL||49.6 ng/mL|
In this example the competitor offers an anaemia control with lower levels of TSH, Vitamin B12 and Ferritin at an additional cost. With Randox Acusera QC, only one control is required for anemia monitoring and detection.